Double hung window sash



Jan. 31, 1956 P. L. ADAMS ET AL DOUBLE HUNG WINDOW SASH 2 Sheets-Sheet 1 Filed July 11 1950 m m Am 0 mm W WM Wm M C MN Jan. 3 1956 P, ADAMS ET AL DOUBLE HUNG WINDOW SASH 2 Sheets-Sheet 2 Filed July 11, 1950 United States Patent 2,732,594 DOUBLE HUNG WINDOW SASH Paul L. Adams, Wayne A. Norman, and Charles K. Sitterly, Dubuque, Iowa, assignors to Carr, Adams & Collier p y, b ue, Iowa, a t m ta i n o Iowa Application July 11, 1950, Serial No, 173,192 2 Claims. (Cl! I l-:52)

This invention relates to a double hung window sash, and particularly to the provision of ,counterbalancing springs therefor which are mounted in place for operation in a novel and improved manner.

Most balancing window sashes employ either weights or springs as a counterbalancing means so that either sash will remain in any selected vertical position of adjustment. One of the principal disadvantages of the usual spring counterbalance is the fact that the tension exerted thereby varies according to the vertical adjustment of the sash, and consequently a true or even balance cannot be uniformly maintained.

A primary object of this invention is to utilize with each double hung window sash a so-called negative spring whose tension remains uniform regardless of the adjusted position of the sash. A spring of this character is well known at the present time. The means whereby such a spring may be utilized in a double hung Window sash is a special feature of this invention. According to each of the several different exemplifications hereafter disclosed, the coiled end portion of such a spring is mounted within a recess provided either in the sash or in the window frame wherein the sash is mounted; and provision is also made for confining, the uncoiled portion of such a spring against lateral deflection for substantially the full distance between its coiled end portion and its opposite end which is anchored to the sash or to the window frame, as the case may be.

These as well as other objects of our invention, as will hereinafter appear, may be realized from the severalconstructions illustrated in the drawings wherein.-

Figure 1 is a vertical elevation, partly in section, showing a pair of double hung window sashes together with the window frame wherein such sashes'are mounted;

Fig. 2 is a fragmentary vertical section through-one stile of the lower sash and the aligned stileof the upper sash, showing in elevation one of the counterbalancing springs connected thereto and to the window frame wherein the two sashes are slidingly mounted; Y

Fig. 3 is a horizontal sectional view, taken on line 3-3 of Fig. 4;

Fig. 4 is a vertical section taken through one stile of the lower sash, showing in elevation one of the spring counterbalances and its connection with the. window r m Fig. 5 is a vertical section, taken on line 5?5 of Fig. 6, showing an alternative construction of the spring end which is affixed to the frame;

Fig. 6 is a similar view, taken on'line 66 of Fig. 5;

Fig. 7 which is a view similar to Fig. 5, shows a further alternative construction of the spring and which is aflixed to the frame;

Fig. 8 is a detail in section, taken on line. 8-,8 of Fig. 7;

Fig. 9 which is a fragmentary vertical section, taken on line 9-9 of Fig. 12, shows; a modification in that the mounting for the jamb of the window frame;

h in cannibal-ante i l ated i 2,732,594 Patented Jan. 31, 1956 ice Fig. 10 which is a similar view, taken on line 10-40 of Fig. 11, shows a further modification in that the mounting for the spring counterbalance is in the head of the window frame;

Fig. 11 is a fragmentary horizontal section, taken on line 11-11 of Fig. 10, showing one form of confining guide for the straight end portion of a counterbalancing spring that is mounted in the window frame; and

Fig. 12 which is a similar view, taken on line 12.12 of Fig. 9, shows another form of confining guide to prevent lateral deflection of the straight end portion ofthe counterbalancing spring.

The present window sash assembly comprises a frame F of the usual type having a head 10, side jambs 11, and a sill 12, the frame 'jambs each mounting a resilient Weatherstrip W which provides suitable guides for upper and lower sliding sashes U and -L. Each guide is further defined by a blind stop 14 on the outer face of the jamb and an inside stop 15 interiorly thereof. The weatherstrip is also formed with a wide central rib 16 constituting a parting stop which is extended vertically between the upper and lower sashes in the usual way.

As is customary, each sash comprises top and bottom rails 18 and 19 interconnected by stiles 20, thereby defining a frame wherein is mounted a pane of glass or the like. Each Weatherstrip is also formed with a pair of ribs 21 which coact with complementary grooves 22 in the stiles of the sash.

The parts thus far described are common to each of the several constructions hereinafter to be described, even though they may differ somewhat in various details, and the same reference characters are accordingly applied to all such like features.

Considering first the construction of Figs. 1 4, the grooves 22 in the sash stiles are located relatively close to (a) the inner face of the upper sash U and (b) to the outer face of the lower sash L, thereby to leave ample room for an adjacent channel 2-5 having opposite beads 26 extending toward each other to provide, in effect, a partial closure therefor. Each channel is also formed with a longitudinally extending base recess 27 of somewhat lesser width for a purpose which will already appear. Near its lower end each channel opens out upon a recessed pocket 30 whose upper side is equipped with a bearing plate 31, desirably of a graphited phenolic composition.

connect releasably with a hook H that is aflixed to the frame jamb 11. This spring S is of the self-coiling type, sometimes known as a negative spring. It is a flat metal ribbon, highly prestressed in manufacture, so that ittends naturally to coil with its turns lying tightly upon each other, as shown in Fig. 2. The coiling torque opposes the uncoiling pull, so that a force must be exerted to straighten out the spring, and such a force is developed only by that portion of the spring that is straightened as it is drawn oil of the tight coil. The length of each spring is such that a coil is always present within the pocket 30, regardless of the adjusted position of thesash with which it is associated.

The hook H, as best shown in Figs. 2 and 3, comprises a base 35 apertured to receive a fastening screw 36 that is anchored in the jamb 11. This base is provided with an offset head 37 from which is laterally extended a U-shaped hook terminating in a tongue 38 which closely approaches the frame jamb 11, preferably at an acute angle as clearly indicated in Fig. 2. By-the offset provided in its base, the hook H remains clear of formed with an eye 3S to receive the hook tongue 38, thereby establishing a releasable connection between the free end of the spring and the jamb 11. The torque of the spring is such that it maintains a constant tension outwardly at its free end whereby to prevent its disconnection from the hook. The hook lies in the path of the sash so as to enter its channel 25 and occupy a position within the base recess 27 (see Fig. 3) when the sash is vertically adjusted to a position of covering over the hook, all interference with full range sliding movements of the sash being thereby avoided.

In operation, when the lower sash is in down position, each spring S is self-coiled for only a minor part of its length (see Fig. 1). In this condition its straight portion 33 is maintained under tension so as to counterbalance the weight of the sash. This tension force remains substantially uniform throughout the entire range of upward sliding movement of the sash whenever the latter is to be adjusted to any of its open positions. The position of the hook H for the spring S of the lower sash is above the latter at a point opposite the upper sash U so that the spring will be effective for the full range of upward sliding movement of the lower sash to exert a counterbalancing force thereon.

The upper sash is provided with a pair of counterbalancing springs each of the same character as the pair already described in connection with the lower sash. These springs S are similarly mounted and connected to hooks H which are desirably located at the same height as the hooks which connect with the springs S for the lower sash. This is entirely feasible since the two sashes are mounted to slide in separate paths, each hook being disposed in the path of its associated sash (see Fig. 3). When in closed position, the springs S associated with the upper sash U are coiled for the major portion thereof, as contrasted with the springs of the lower sash which, when in closed position, are coiled for only a minor portion of their lengths. When the upper sash is lowered, however, the springs S which serve as a counterbalance therefor are required to uncoil, and at the lowermost position of the upper sash only a minor portion of the length of the springs S remains coiled within the recessed pockets 30 which are provided therefor.

Referring now to Figs. and 6, we have shown a slight modification in the connection for the free end of each spring S. According to the construction here shown, no hook is required, but instead a leader is connected to the free end of each spring S. The leader may be of sheet metal, substantially inflexible, and formed with an enlarged base section 41 connected by an inclined section 42 to an offset connecting section 43 where rivets 44 or other fastening means are extended therethrough and through the free end of the spring S to establish a fixed connection therewith. The base section of the leader may be provided with a key hole slot 45 through which is extended a headed fastening element such as a screw 46 for anchoring in the jamb 11 of the window frame. In this construction, since we use no hook requiring accommodation beyond that furnished by the channel 25, the base recess 27 shown in Fig. 3 may be omitted.

In Figs. 7 and 8, we have shown a similar construction except only that the free end of the spring itself is formed into a leader comprising an inclined section 48 connecting with a base section 49 having an aperture for receiving therethrough a fastening element such as a screw 50 which is anchored in the jamb 11 of the window frame. In use and performance, a spring constructed as per Figs. 7 and 8 will operate the same as the one just described in connection with Figs. 5 and 6.

In the construction thus far described, the pocket 30 provided for reception of the coiled end of the spring has been formed in one of the stiles of the sash, and this is a satisfactory expedient for the purposes of our invention. However, it is equally feasible to provide such a pocket in the jamb 11 of the window frame as suggested in Fig. 9. Here the pocket 50 is formed in the jamb 11 to receive the coiled end 52 of the spring S whose free end is formed with an offset base 53 for connection with the associated sash L or U, as the case may be. The location of the pocket 50 vertically of the jamb is such as to position the spring properly in relation to the sash with which it connects so as to exert a constant counterbalancing force thereon. A bearing plate 54 similar to the plate 31 previously described is desirably positioned within the pocket 50 to withstand the friction encountered from the spring when coiling and uneoiling movements are taking place; and we may also attach in place a closure plate 55 which provides for the pocket a barrier sufiicient to confine therewithin the coiled end portion 52 of the spring S. The ribbon spring is then passed through or over the closure plate 55 when being drawn tangentially from the coil which is contained within the pocket. A screw fastening 56 is indicated as a suitable means for affixing the closure plate in place.

A similar expedient is illustrated in Fig. 10 where a pocket 60 is formed in the head 10 of the window frame. In this construction a combined closure and bearing plate 61 is secured as by one or more screws 62 over the bottom opening into the pocket to secure therein the coiled end 63 of the spring S which passes outwardly therefrom through a slot 64 in the plate to depend toward the proximate slash L or U, as the case may be, for offset connection therewith, as shown. The operation of a window sash having a pair of counterbalaricing springs of the self-coiling type, when mounted in the window head as shown in Fig. 10, is the same as that already described in connection with the other figures of the drawings.

In the arrangement of Figs. 10 and 11, the straight portion 66 of the spring S is desirably confined within a channeled guideway that is formed in or affixed to the window frame. Such a guideway may be provided by a slot 65 that is formed in one of the stops 14 (or 15) afiixed to the frame jamb, this slot being so located as to receive the spring straight portion 66 as its length changes with variations in the vertical position of the sash to which it is connected through a laterally extending fitting 59. In lieu of the slot-guideway just described, there is illustrated in Figs. 9 and 12 a channel strip 58 affixed to the jamb 11 and disposed upon its inner face (as shown) or recessed therein, as preferred. The spring straight portion 57 which is thus confined within such a channeled strip is connected at its free end to the associated stile 20 through a suitable fitting 53 which is sufficiently narrow to enter the channel without being confined thereby.

One feature of our invention is the simplicity of the involved structure, and the facility with which the counterbalancing springs may be installed. In each case the recessed pocket may be formed at the mill prior to shipment of'the frame and sash. Springs of the requisite length and strength, and also anchoring hooks, if used, may be included in the shipment. The operation of installation is mostly one of assembly. In use, the springs do not need to be confined within their mountings if these be provided in the sash (see Figs. l-4), nor is any pivotal support required for springs when placed within the pockets that are provided for their reception. The coiled .end portion of each spring is-free to rotate within its 'mounting any time, in either direction, when conditions permit. A bearing plate in each case may be used to minimize friction and prevent wear of the wood surface whereon a constant pressure is maintained by the coiled end portion of the spring. Furthermore, in the construction of Figs. 1-4, the bearing plates do not require anchoring in their respective pockets, since they are confined in place by the coiled end portion of the associated spring.

A further feature of advantage is the provision of -means,-extending for substantially the full distance between the coiled end portion of each spring and its anchored free end, for confining the spring straight end portion from lateral deflection. The self-coiling properties of the springs used, to provide a constant force counterbalance for the window sash, are such that the coiling torque persists throughout the straight end portion of the spring as well as elsewhere. Since a major part of this straight end portion of each spring is disposed within the narrow space between the sash stile and frame jamb, it is highly important that it be guided and confined properly to prevent tangling and snarling. Such a guide is the confining channel in each of the various forms hereinbefore described. Without such a confining guide the operation of uncoiling the spring is both diificult and hazardous, due to its tendency to twist and tangle with considerable force and speed. In the absence of a confining means such as we have provided, it would be necessary to insert the sash in the window frame preliminarily and then extend each spring between one sash stile and the adjacent frame jamb with the aid of a wire or other contrivance that is attached to the spring end for this purpose. By providing in the construction of Figs. 1-8 the confining guide herein disclosed, each sash, while still at the factory, may be equipped with its balancing springs Whose coiled end portions are fitted within the recessed pockets to permit the straight portions thereof to extend within the channeled guideways to and beyond the remote sash end where each spring is selfcoiled into the form of an inwardly turned hook to engage the sash rail at that point.v In this position the springs are maintained under tension, ready for attach ment to the hooks which are anchored to the frame, whenever the sash is operatively fitted thereinto. This makes it possible for the factory to equip each sash with springs of the proper size and strength, to ship the sashes and window frames separately so that one may be assembled with the other on the job, and to facilitate connection of each balancing spring to the associated window frame by a manual operation without the aid of any tools. To remove the sash the tensioned ends of the springs are depressed for disengagement from the hooks whereupon the spring end portions will self-coil inwardly to engage the proximate sash end whereby they are maintained without further attention.

We claim:

1. In combination, a window frame having opposite jambs, a sash having opposite stiles and top and bottom rails, each of the stiles being formed with a vertical confining T-shaped channel adjacent their respective jambs terminating at its lower end in an outwardly opening recessed pocket, said channels extending along the length of the stiles from said pockets to the top rail and having the base of the T-shaped channel opening toward the adjacent jamb, a prestressed, self-coiling ribbon spring rovingly mounted in said pocket and having a portion of its length extended tangentially therefrom into and through said confining channel, each of said channels having confining sides acting to confine said spring and prevent deflection of the spring due to the prestressing thereof, a reverse hook for holding each spring constructed to utilize the spring torque in holding the spring thereon, said hooks being anchored to the jamb at a position just above each stile when the sash is in its lowermost position and comprising a mounting extending outwardly away from the jamb to a position overlying the window sash and a tongue extended generally horizontally and inwardly therefrom toward the jamb, the spring near its free end being provided with a slot for reception of the tongue to releasably connect the spring to the hook whereby to maintain constant tension counterbalance on the sash, the torque of the spring adjacent the hook urging the free end of the spring away from the jamb and toward the tongue mounting to assure maintenance of its connection with the hook fitting, said hooks also being vertically aligned with said T-shaped channels andof a size smaller than said channels so that raising of the sash will cause said channels to receive said hooks and permit continued elevation of the sash.

2. In combination, a window frame having opposite jambs, a sash having opposite stiles and top and bottom rails, each of the stiles being formed with a vertical confining channel adjacent their respective jambs terminating at its lower end in an outwardly opening recessed pocket, a prestressed, self-coiling ribbon spring rovingly mounted in said pocket and having a portion of its length extended tangentially therefrom into and through said confining channel, said channels having confining sides acting to confine said spring and prevent deflection of the spring due to the prestressing thereof, a reverse hook for holding each spring constructed to utilize the spring torque in holding the spring thereon, said hooks being anchored to the jamb in vertical alignment with said channels at a position just above each stile when the sash is in its lowermost position and comprising a mounting extending outwardly away from the jamb to a position overlying the window sash and a tongue extended generally horizontally and inwardly therefrom toward the jamb, the spring near its free end being provided with a slot for reception of the tongue to releasably connect the spring to the hook whereby to maintain constant tension counterbalance on the sash, the torque of the spring adjacent the hook urging the free end of the spring away from the jamb and toward the tongue mounting to assure maintenance of its connection with the hook fitting, said confining channels being shaped so that the spring hooks may be received therein as the sash is elevated so that raising of the sash will cause said channels to receive said hooks and permit continued elevation of the sash.

References Cited in the file of this patent UNITED STATES PATENTS 1,226,843 Arvine May 22, 1917 1,665,697 Glaser et al. Apr. 10, 1928 1,745,578 Kreissig Feb. 4, 1930 1,897,010 Pollock et al. Feb. 7, 1933 1,925,059 Sheard et al Aug. 29, 1933 2,101,577 Gossen Dec. 7, 1937 2,121,714 Rose June 21, 1938 2,284,436 Lundgren May 26, 1942 2,295,689 Renton Sept. 15, 1942 2,609,193 Foster Sept. 2, 1952 FOREIGN PATENTS 1,828 Great Britain Jan. 26, 1899 OTHER REFERENCES The Ironmonger, October 27, 1888, issue, page 139. 

